Solid fertilizers, such as urea and ammonium sulfate, provide nutrients to the soil. Many solid fertilizers are hygroscopic, which can result in stickiness, clumping, and caking when the fertilizer becomes wet. This clumping reduces the flowability of the fertilizers and complicates their handling. These complications can also arise when the solid fertilizer is stored in a humid environment or contacts water or a water-containing solution, such as fertilizer additives. Furthermore, untreated solid fertilizers may produce dust when processed, leading to decreased performance for the equipment used in processing.
Absorbent materials, such as attapulgite clay, diatomaceous earth, and urea formaldehyde polymers may be blended with granulated solid fertilizers and provide some relief from these complications. In some instances, farmers may use explosives to break apart clumped stockpiles, endangering themselves and those nearby. In other instances, removal of loose solid fertilizer leaves clumped sections of the stockpile, which form bridges prone to dangerous collapse. These approaches, thus, are inadequate for improving the flow of solid fertilizers exposed to water and/or high humidity.